Automatic district telephone system.



H. E. HERSHEYI Auofvmm mmm ELEPHUNE SYSTEM.

APPLSCHOW FILED HIGH?, EW

1,283, 182. Mmmm oct. 29, ma.,

5 HEEiS-*SHEEI I.

l 1f Q IMUR H. E. HERSHEY.

AUTOMAUC DiSIRICT TELEPHONE SYSTEM.

APPLlcMioN mr" we@ m4 1,283,182i Patented om. 29, uns..

5 SHEETS-SHEI 2.

BHI

H. E. HEHSHEY.

AUTOMATIC DiSUICT TELEPHONE SYSYEM.

APPucmsoN mm Anas. 1914A 1,283,182. Patented oct. 29, uns.

5 SHEETS-SHED 3.

MTA/55555 fvwm/TOR:

HHH/wf E. HSRh/Ex /77 TOR/vins! H. E. HERSHEY.

AUTOMAHC DISIRICT TELEPHONE SYSTEM.

APPucATmN min AuG.s19\4.

ESHEETS-SHEE 4.

H. E. HEHSHEY.

AUTUMATIC DISTRICT TELEPHONE SYSYEM. APPLxcATmN FILED was. 1914.

1,283,182. Patented Oct. 29, 1918.

5 SHEETS-SH EET 5.

@TOR/vara.

UNITED STATES PTENT oFFIdE, e,

HARRY E. HERSHEY, OF-WHI'IEWATER, KANSAS, ASSIGNGR T0 AUTOMATIC .ELEOM COMPANY, orionrcaeo, ILLINoIs, A.' conPonATI'oN or ILLINoI" AUToMA'rIc DISTRICT TELPHNE SYSTEM.

To all whom it may concern.'

Be it known that I, HARRY E. HERSHE'Y, a citizen of the United States of-America, and resident of Whitewater, in the county of Butler and State of Kansas, have invented certain new and useful Improvements in Automatic District Telephone Systems, of which'the following is a specification.

.My invention relates to automatic district telephone s stems-that is, systems in which the subscri ers lines terminatel in different offices or exchanges, and trunking connections are providedy between these different exchanges in order to providefor the establishment of a connection between subscribers lines which terminate in different exchanges. l

The objectof my invention is to provide improved trunking apparatus fonestablishing connection between lines in'such a system, and to provide means whereby a coni' nection which islocal to any exchange can 'be made through apparatus local to that articularoflice, while when a call is made rom one exchange to another, apparatus at a main or central @Hice is automatically brought into .use to establish such -connec- 115.1011. B my invention I provide a repeating mec anism. which, through its o erationsfdetermines whether a call sha1 be made through the'apparatus local to a branchlofiice, or whether the call shall pass through to the apparatus at a main exchan e. Thus if a subscriber wishes to call anot er subscriber in the same exchange, the

' repeater operates to eliminate the apparatus at the main. office and to permit.the cull to pass through. apparatus local to the subexc'ha'ge. If, however, the subscriber Wishes to call a subscriber whose line terminates in another exchange, the repeater then operates to extend the lconnection (hroughthe apparatus at the main exchange. 45 l My invention will be more clearly understood by reference 4to the accompanying drawings, n'which I haveillustruted the same in connection. with a telephone system employin switches of well-known types.

In the rawin s Figure 1 represents diagrammatically t c layout of a multi-ofiice telephone system embodyinlg the principles ofthe invention disclosed' ercin.

Fig. 2 is a diagramhowing more in de- Speuioetion ot Letters Patent. patentedoct. 29, 1918, Application med August s, 1914. smal No. sismos. i

i l tail the trunking arrangement o fia portion of the system shown in Fig. 1; u Y j Figs. 3,4, 5 and 6 show a com `lete connection between a calling telephone '1" and a called telephone T in the system shown herein. it 60. Fig.4 7 is a modified detail. i) As shown in Fig. 1, the` system Cuepresented herein is a multiplelcioefov` d" tritativ system com risin a, lure ityr o -`exe af Y @mees A, npc, D,gA',1=, Bfma., .fihi e5 respect to the trunk connections bei. offices, these are divided intcytwocl The offices A, B, C and D are eachptuinected with each of the others by a separatev set of trunk lines, and orconvenence these) offices will be designated as main ofiices` The offices A', A2, B', B, etc.,.are each connected by trunk lines with only the nearest main oliice A, B, CorfD, as the caselav y be. The onces A',.A2,IB' ,B3 am., wiil'va be termed branch offices. lin a system of this character, when a subscriber Whose lne terminates at one of the main offices, the ofiice'A for exam le, wishes to, communicate with a subscl" er whose line terminates at one of the othermain ofices,-` the4 ofce C,

for example, the calling subscribers line is connected through the medium yof Suitableapparatus at his ovvp ofiice (ofiice "'A) with a trunk line leading directly totheoiiice of the calledfsubscriber (oflice C), at which ofiice said trunk line is connected with thel line of the called subscriber. If subscriber of one o1e the 4branch oflices (office 'A, for example) Wishes to call a ,sub- 90 scriber of some other ofiice, he mustV first obtain connection with a trunk line leading *Y to his main office (otlice A). At this ofiice connection may be made with a trunk line leading to the office of the called subscriber providing the called Subscribers line` terminutes in one of the main o ilices, or in-, another branch oflice (such as the -ofice A*) which is connected with .the sume main office as the calling subscriber. If the called sub- 10o scribers line terminates at a. branchofiice (office C', for example) of a secondmain oilice (ofiice C),'the calling subscriber, after having obtained connection over a vtrunk line with apparatus in his o.wn main ofice (ofiicc A). must then obtain connection ,with

a trunk line leading toy said Second main Yoffice (oice C), and then, through the mef.

dium of apparatus at said second oilice, be connected with a trunk line leadin to the branch oilice (office C) of the cal ed subscriber, where the connection is finally completed. Following out this eneral plan, 1f a subscriber of a branch o ce desired to obtain connection with a second subscriber of the same branch office, it hasheretoforc been necessary that he rst obtain connection with a trunk line leading to a main oice with which his branchroilice is connected; and would then obtain connection with a second trunk line leading back from the main oliice Vto the branch oiiice, from which said second trunk line connection ywould finally be completed .with the called subscribers line. Bv my invention, however, the trunk lines leading from thei branch oiiice to the main office and back from the main office to the branch oiiice are excluded from connections between the subscribers of the same branch oilice, said connections being established entirely bv appal ratus local to the branch oice.

Referring to Fig. Q, the method of carrying out my invention is in general as follows: The apparatus inclosed within the dotted lines represents the apparatus of a branch office, while the remainin apparatus is assumed to be local to a main o ce. There are shown in this figure two groups of substribers substations T3 and Tf, the line conductors of each of which terminating in an individual trunk-selectin or preselector switch E at the branch o ce. For the purpose of being called, these lines terminate in the banks of a plurality of connector switches F. These connector switches are represented herein by small circles, the three parallel lines underneaththe same representing the multiple bank contacts which are assumed to be arranged in horizontal rows or levels. T he individual switches E of each of theV groups of subscribers substations T3 and T have access to a group of trunk lines t which lead to Socalled seconder trunk-selecting switches H. The switches have access to trunk lines t which lead to first selectors I inthe main office. Associated with themain oice there are shown two 'groups of subscribers substatons TE sind rovided with a group of reselectin or line switches at the central o ce for ca ing purposes, and with connections in the banks of connector switches F for being call Each of the groups off line switches E has access to a group of first selector switches I, which first selectors in turn have access to second selectors J Although the bank` contacts of all the first selectors shown in Fig. 2 are represented as being m'ultipled together, -it is to be 'understood that this igureis only diagrammatic, and

any known or desired multiplmg arrangeeach o'f which groups is` nasales ment of the selectors may be employed. As shown herein, the first level of the first selectors has access over trunk lines 2 to second selectors J in the same exchange. The remaining two levels shown are assumed to have access to groups of trunk lines t" and t* leading to other main oflices, where said trunk lines would terminate in second selectors. In like manner, the main olice is provided with groups of second selectors J which are accessible through the iirst selectors of the other main oflices in the system. The third and sixth levels of the second selectors J have access to trunk lines leading to line switches Z in the branch oiiice, which in turn have access through the medium of connectors F to the subscribers lines T and T. The remaining levels of the same group of second selectors have access to connectors having access to the subscribers lines in the main ollice. The remaining groups of second selectors may have access to connectors all of which are situated in the main cfiice, or some of which are situ-- ated in a branch office and some in the main office, or in any manner desired. In each of the trunk lines t which lead from the subscribers individual switches E to the secondary switches H there is a switching device L which, under certain conditions, may operate to connect the trunk line which has been seized by a subscribers individual switch with a connector in one or the other of the groups of connectors which have access to the branch office subscriber groupsT.

and T. Y

In general the 4poration of the system shown in Fig. 2 is as follows: Upon the removal of the receiver from the switch-hook by the subscriber of one of the brancholle groups, his individual line switch E operates to select a trunk line leading to a secondar` switch H, which in turn operates to select an idle first selector I.. The subscriber operates his calling device to cause the selected first selector to extend connection4 to an idle second selector in the section or division of the exchange to which the called subscriber belongs. The selected second selector is then operated to extend the connec` nector is then operatedito establish connection with the called subecribers line. yAssuming now that the called subscriber is in the same branch office as the calling sub scriber. Under these conditions, when the calling subscriber operates his callin device to cause the second selector to esta lish connection with a connector switch, the' switching apparatus `L in the c trunk line i which has been seized by the calli -subscribers line switch operates to extend the connection directly to one of the connectors H and switches the call over to the local con' nectors F. When the apparatus L thus operates to extend the connection to a local connector,l it causes the secondary switch H which was previously selected, as well as all the selectors which have been o eratcd in the main otlice, to be released an(A the connection is therefore confined solely to the branch oflice.

The apparatus with which I have chosen to illustrate my invention is of a well-known type and is shown in patents of the prior art, and it is therefore thought necessary to show only such details of construction as are necessary to bring out the novel features.

The telephonesubstation T (Fig. 3) comprises the usual receiver 2, transmitter 3, switch-hook 4, ringer 5 and condenser 6. Beingan automatic substation, it is also provided with a suitable calling device or impulse transmitter which is represented herein by a pair of impulse springs 7 and 8 and an impulse wheel 9, which latter may he operated by the calling subscriber through lthe medium of a finger hole dial (not shown) to cause the impulse springs to be opened a number of times corresponding to the digit which it is desired to call.

The subscribers individual switch E (Fig. 3), which may'represent any of the switches E shown in Fig. 2, is of the general type of switch disclosed in British vpatent to R. W. James No. 26.801 of 1900, bc ing of the more particular form shown.in British patent to A. E. Keith No. 1419 of 1910. This line switch, as is well known, is provided with a movable plunger which, when idle, is always maintained opposite the bank terminals of an idle trunk line by a so-calledr master switch. Upon the operation of said switch its plunger is forced into the terminal springs of said trunk line to connect the subscri ers line therewith. The switch Z is similar in all respects to the switch E.

The master switch N is of the same general type as that disclosed in British Patent No. 26,301 of 1906, referred to above. being` however, of the particular type disclosed in saitLBritish Patent No. 1419 of 1910. The function 41f the master switch` as is well knowmis to maintain the plungcrs of all idle switches'in,-position to engage the terminals of an idle trunk line. 2The apparatus shown at L (Fig. 3) is one of the switching devices shown at L in the diagrammatic Fig. 2. This device pert'orms two functions. In a call 'from the branch oice to the main otlice, it operates as a repeater torepeat the impulses from the calling substation to the trunk extending to the central station. ln a local connection this device operates to i'ree the trunk line lending to the main otlice and to divert the call to the proper local switches for completing the desired connection.- This switching repeater comprises a vertically and rotatably movable switch shaft (not shown) which carries the wipers (i5, 7T, 112 and 113 and is controlled by the vertical magnet 59 andthe rotary magnet 64 in the manner shown in United States Letters Patent No. 815,321, granted March 13, 1906. to Keith, Erickson and Erickson, for improvement in selector switches. These operations are controlled through the medium of a doublewound line relay 18 which is connected with the line conductors through the springs of a reversing relay 51. The relay 51 is double-wound and is so adjusted that it is operatively energized only when both windings are energized in the same direction. The line relay 18 controls a second bridge across the. trunk conductors for the purpose of repeating impulses to the main exchange in a 95 manner to be hereinafter more fully explained. The magnet 74 is the usual release magnet for restoring the switch shaft and side switch to normal position upon the release of the connection. However, the re- 100 lease magnet is adapted to release the switch shaft immediately upon energization, rather than upon the deiinergization thereof as shown .in said selector patent. This release magnet is conn ted in series with a douhlewound relay 73. The, switching repeater L is also provided with a .so-called side switch similar to that shown in said selector patent. together with two relays 28 and 58 which are slow acting-that is, relays which dcncrgize slowly after their energizing circuits have been broken. There are ten rows or levels of bank contacts for each of the wipers 05, 77. 112 and 113. The banlrcontacts accessible to the'wipers 112, (i5` and 115 113 of the levels com'esprindng to the branch exchange in which the lcpeatcr L is located arc lnultiplcd between banks, while the contacts in each level of the bunk accessible to the wiper 77 are connected together, and the 120 levels which correspond to the groups'of connectors in the' branch exchange are connected to thc lett hand spring 70 of the relay` T3 of each repeater L. Also in the bank associated with the wiper 05 the first contact 125 in the level corresponding to the main ottico with which the branch ollice is connected is connected with the lsprings 7l of the relay 73. For example. it' the numbers in the branch office begin with the digit 5, whenover the diei is operated for the first digi?, 5 the wipers will lie raoeeff to rire ii'fth level, and upon eutin f in upon ille first contact in said level wil close u circuit which will cause the releuee oi this Switch, at the time causing a groom-i to be placed upon all the contacts :weee-sible to lle wiper JT which ure connected with the Spring TT). Il ille liret digit called oy the first operation of the dial is other than 5, the switoh will not be released,bilt will come to rest upon tlne first ooratart in th(` level to whirl! ii has been raised, but should this level 'oe our wl oli leads to the local connectors, the ewitfhing relay 174 will not be operated for the reason time at Vthis time there no ground ou tile Spring beroering upon u bunk om leedirlg to e connector, and the ezwxrio, E 'im not euerglzed, the Contact in le not malle busy, for the swioli rioes; not plone u grouml upon it"` privee@ wiper rv" u said. wiper is in third position. After the first diffit 5 has been rolled. should the next digit cn ed be that of u group of ronuortors ai; the branch ollice, the switch upon coming to rest upon the Siret idle Contactin that. level, will here its switei 115.: relay lT-i energized, due to the ground now upon the spring T6.

The seconfory switch il (Fig, 5l. which corresponds to one of the Switches; H, is the same in principle the subscribe/rie individual ewitoa E2 'being' somewhat simplilied, horror-eri ir that it is 'not provided with line or r 113' orouwturosi Tli switch belong-5 to a. which Corb trolled by e muster ,sli not elimini similar to the master Sexolf: lil

The selector switches I and JQ which may represent any of the i ecrire Switches I 0r J 2), me o? t-x gener-ei type oi selector switches Lommel in seid Letters Patent No. 815.32'1, above 1 erer to being somewhat mwiied, lioweer., shown in British Patent No. 1411?# of ii, lieroim above referred to, so ogm-nrs 'in e twowire system. The misnomer; o ewirah cuirs being e cool mi. "li iii ileif, r .fienile i likewise dispensed with, ilu further slightly moeliir' en Referring to 'the solo Y switfhee comprises uw Y bank of contacte Mmmm@ and adrpetl to ou envi/.g wipers 95, 98 and 99 wlllrlr vertically sin' mobi-f; mov

by oi corrieri mio eliut {riot sh0wn} wil rollo-fi i usual rerticul and rotary megnee T. aofi l'ij usual release magnet l efioped to i' lease the ewoi shaft irmmariareijf enorgizatiemll retirer than by the ration thereofY as shown iio i Sel or ent. The refiere 55 and ut eow f The connector switch F', Wheh may correepomi to orly of the connector switches l? {Fig 52;, le of tlae refiere?. type of connector shown iu 'United i tutes Letters Patent No. Sl', granted Marel; 13, i905, to Keith, fflrioll ou and, Erickson, being modified, lowover, in orler to operate in a tW' -Tvire System. The switch comprises among other details a bank of contacts arranged in rows or levels which are adopted to oe engaged by e set of wipere l', 117 and 118, which wipers are corrieri by a, vertically and 1'0- mtubly movable shaft (not shown) which is controlled oy the ueual vertical and rotary magnets i2@ end .'12 The usuel eide switch controlled by tile private magnet 122 in the well-known mannen The usual release magnet 123 is aapted to release the switch shaft irzimeiidtely upon onergizrrtion, rather than oy the denergization thereof, as shown in said Connector paient, At 124 is shown the ring-er 'relay by nieuwe of which ringing Current is proiootefi onto the milled lino. The relays 1.43 and 2526 are slow acting. The connector l similar in all respects to the oonowtor li".

The telephone Substzirion T2 :md the i11- rlividuel avvii-cir E2 in all respects the saune as the telephone eu'nstation T und elle Switch. E Fig.

t (Fig. 6) there is represeuro-'l u ring ing ourreot generator and at Q erown :i busy signaling machine, While the burieriee X. euri X are for supplying' current for operai' the central office apparatus uml for igoixing purposes.

''aviug a. general description of the erstem and apparatus in connection with l1 has jeen cfliosonrto illustrate the iilreiiieion (iiscla'isod herein, there will now lie given a more or less detailed cleseription of the ogeietions ""ny Wliicli the connections are pero. lished between the various oui sieno# ek Siu-e the appfuumas eiiown herein is in general well known in the ort, und is fully doecriined in the publioatious herein reoriui tos it is not thought necessary fao des@ ue its operation in detail i'aerein, .it will liest ho explained how e eormection is extentie-,d from tile toleplione substation T of o, branch ollice to a telephone substation T2 the mein oliioe, our, of which latter o'ee the seid brauch oloe. operates, The

ibi]

number of? the selling subsi-ation will be upon euergiziug, the murature 10,

whereby rirour is closed through the pullyin winding 11, which operates to attractthe `the springs 111 and 15 and 17 and 16 to the switching repeater L', while the armature 13 operates' 'to disconnect the winding 209 from thev line. W'hen the connection is extended to the switching repeater, a circuit is closed through its line relay 18, said circuit extending from' ground G through the lower winding of the relay 18, relay springs 19 and 20, re ay springs!` 21 and 22, line springs 16 and 17 to and through the substation T', line springsland 15, relay springs and 24, relay springs 25 and 26 and the up er winding of lthe relay 18 to battery X. he relay 18, upon energizing, closes a circuit from ground' G2 through thefront contact of the spring 27 and the relay 2 8 tobattery X. One result of the energization of the relay 28 is the clos'ureof a circuit extending from ground G3 through the springs 29of the rclay 28, springs 30 and 31 of the relay17-1, private line springs 32 and 33 and the holding windingil to battery X. The winding 34, upon energizing, serves to hold the switch E in its operied position after the line Windin has been disconnected from the line and bro en the circuit of the wind-in 11. A further result of the energization o the relay 28 is the closure of a circuit extending eov from ground Ga'through the springs 29, conductor'- 35, Winding 36l of the secondary switch H (Fig. 4), springs 37 and 3S and the springs on a master switch (not shown) to battery X. The switch H thereupon operates to extendV the connection through the springs 40 and 41 and the springs l2 and 43' to the selector` I', while at the same time, by the shifting of the spring 37, the winding 36 is connected with the battery lead through the high resistance winding T41, so as to reduce the holding'current ot' the switch H. A further result of the encrgization of the line relay 18 when the connection is first extended thereto is the closure of a bridge across the trunk conductors -45 and @6, whereby, as soon as `the connection is extended to the first selector I', as above described, an energizin i circuit is closed for the line relay 4T. lhis circuit extends from "ground G through the lower winding of the relay 47, sp1-ings 48 and 49, springs 13 and 42, conductor 4G, coil 50, the right-hand winding of the relay 51, springs 52, conductor 45, springs 40 and 41, springs 53 and 54 and the upper winding of the relay 47 to battery X. The relay 51 is not operatively energized at this time because only 4one winding has current flowing through it. The relay 47, upon energizing,

. closes a circuit through the slow acting re- 4lay 551.

The foregoing operation takes place immediately upon the removal of the receiver from the switch-hook at the calling substation. his callin device in the usual manner for the first digit 5 of the called number, whereby the substation impulse springs 7 and 8 are separated five times momentarily. Each time the substation impulse springs are separated, the line relay 18 of the switching repeater is momentarily denergized. The breaking of contact between the springs 5") each time the relay 18 dcinergizcs opens the bridge across the trunk conductors 45 and 16, thereby momentarily breaking the ener- The calling subscriber now operates gizing circuit of the line relay 4T of the first selector l. repeater being slow acting does not deiinergize during the momentary iuterru )tions of its circuit by the relay 18, and there orc, each time the spring 27 engages its back Contact, an impulse is transmitted over a circuit cxtendino from ground (i2 through the spring 27 andlits back contact, springs 5G and 5T,n relay 58, vertical magnet 59 and the side switch wiper 60 (in first position) to battery X. The vertical magnet 59 receives five impulses over this circuit and voperates to raise the shaft wipers opposite the fifth level of bank contacts. The slow acting relay is energized by thc first impulse which is transmitted through it and remains in its operated position until after the last impulse is delivered for the digit. In its operated position the relay 58, by placing the .springs G1 in Contact, short-circuits the coil 5() and the right-hand winding of the relay 51. so as to remove their resistances from the circuit of the line relay of the selector l while inipulses are being transmitted through it. The closure of the springs G2 completes an energizing cil-cuit for the private magnet (i3. Upon the breaking of this latter circuit when the relay 58 denergizes after the last impulse for the digit is delivered from the substation, the private magnet (i3 dc'cnei-gizes and permits the side switch to pass to second position. The side switch wiper 60, upon passing to second position, closes a circuit through the rotary magnet 64, which thereupon energizes and rotates the shaft Wipers one step, upon the first contact in the `fifth level. The wiper 65 will meet with no guarding potential upon the first contact of the fifth level, as hereinbcfore described, whereupon the private magnet will deiinergize. At the time that the springs V67, (i8 and (Si) are in engagement, a circuit may be traced from ground G through the springs 67, 68 and 69, Wiper 65, bank contact 70` springs 71 and 72, upper winding of the i'clay 73, release magnet 71 and the springs 165 to battery X. The release magnet will encrgize over this circuit and operate to restore the shaft of the switching repeater to nor- Thc relay in the switching mal, without in any way affecting the first selector I. The relay 73 will he energized in series with the release magnet und, upon operating, will close a looking circuit for itself from ground G through the Springs Q9, springs 30 and 3l, springs T5 and the lower winding of the relay 73 to battery XE The, energization of the relay T3i hy the bringing into eontnet of the Springe 76, ilaeee ground from ground G upon ell the haaltv contacts accessible to the wiper i? which correspond to the groups oP connectors in the branch otliee. Alno the engagement of the Spring T8 with the spring T plaees ground from ground (l'-" upon the nt oontart in the fifth level ivhirh is aoeeeeihle. by the 'wiper G5. The tire iinpulees whioh are tinneuiitted to the line relay 4T of the first selector I by the relay 18 of the switching repeater cause tivo impulses to he transmitted through the vertical magnet il) in aeries with the slow acting rela;v 80, whereby the shaft wipers are lifted tive steps. The :said circuit may he traced from ground G" through the spring 81 and ite hack contat-t, Springs ltv, springs 82 and relay S0 and the. vertical magnet "i9 to battery X. The slow acting relaj)v St) ie inaintnined in its energized position Continin ously while impulse4 are being transmitted to the vertical magnet through it, and in its energized position closes a eireuit extending from ground tl through the Springs El and S5 and therelay SG to mttery X. The relay SG, upon energizing`-` torlnsalcuking oir cuitfor itself extending from ground G through the springs Fl'i and S8, ntl' normal springe 89, springe 90 and Ell and the relay 8f3 to battery X. Thus, upon the lr-enen gization of the relay H0 after the last inipulse is delivered to the vertical magnet, the relay 86 remains energized and the circuit ot' the rotary nnig'netl. ie elosed. Said circuit extends from ground il through the Springs ST, springe 8S, ofi' normal springs 8S), springs Si() and 91,- Springs and U3, springe 94 and the rotary magnet 92 to battery X. The rotary magnet` upon energizing, rotates the wipers one step and, hy openingr the springs S8 and SH, disoonneetn ground G from itsetf and from the relay Sti. lf the tiret trunk line of the tth level is idle, the relay S6 denergizes as soon au the springs 88 nre opened. lf the trunk line is busy, however, the private, wiper 35 linde the Contact which it. engages Vprovided with a guarding ground potential ivliieh is tramanitted through the springs 90 and 91 to the relay 86, the Same preventing the relai)r H from deiinergizing. The rota ry magnet` however `deinergiZes when the springev lll are broken, rovardhise of whether or not the relay Si? remains energized. The eia'euit ol' the rotar) niag'net will again he eloned :uY non un itf-z armature drops bat-.lr far enough lo clone the @ringe S8 "and 94, The rotar}7 magnet will there-- imanes fore opernte in a manner .similar to that ot a buzzer to advanee the wipers Step hy utep over the eontaet until the non-grounded rontart, ot' au idle trunk is reaehed hy the wiper Wn whereupon thr relay HV ilelnergiezee. The relay Sti, upon drinergizing, whether after one or Several nierations ot' the rotary inagnet, permanently hrealrh` the eireuil ot Said rotary magnet and clones the circuit ot the siritehing relay 9G. Said circuit extends troni ground tl through the Springe Si', Springe ott' normal springe 89, springs 9() and lli and the relay Slt? to hattery X. The relair S55, upon energizing, dieonnects the line relay rtl' from the line and extends the line eonneetion throiuglA the wipere 98 and 9i! to the second eeleetor J. The line relav 100 ot' the second selector J' heeoiues energized over a eireuit extending from ground G1 through the lower winding ot' the relay 10U, AepringnL 01 and 102, conductor UZ, over the henry eonduetor to und through the switehing repeater L'.y over the heavyY conduetor to the rouduetor lot, `springe 1%).3 and loll and the upper winding ol' theirelni.V l0() to battery X', The relu;Y lol)7 upon energizing. threes a rirrnit through the slow arting relay lo?, which in turn ation-d5 a holding I rround for the relay $.36 to take the place ol ground tl, which will presentlyY he removed. Said ril'euit extends from ground tl through the springs ltltl Coudurtor 109, privnte wiper 95, springe 5)() and 9i' and the relaiY Siti to hatterj.' X.

The walling suhseriher now operates his N PallinoA devire for the net-ond digit .2 of the twilled nuuiher, in response to whirl; 1tho iuhatt wipers of the siritehing repeater rome to reet upon the tiret contact of the second level in the bank. The second level heine; lead in the hraneh otiiee, its tiret ront-liet will always he idle. 'hen the eide switeh of the selector-repeuter passes to third position, a eirrnt in rinsed through the lefthand windingot" the rela;Y .BL lint the relay fil will not he operatively energized ut this tunem for the current in its two winding@ oppose each other. flu reeponse to the inipulses Heut over the trunk hy the relav 1S, the uerond selector l operates to plinio ite shaft wipers upon the tiret idle eontaet of the eerond level in ith4 hunks and to evtend the lines to the eonneetor 'F' in the saine manner as explained for the selector L. When the line ham heen extended to the non neetor FQ o, rreuit mayY be trut-ed from ground ll through the lower winding of the relay lil-it Springs; 12S and P27, condurtor lfl` over the heavy iionduetor to and through the nwitehing' relxeater L" over the other heavj,y eoudueror to the eondinztor 129. through the `npringrs l'lll and it and the opper wlndinrr ot' the relay lili', to initier-v X. The rela); 123, upon energizing` closes a ritt-uit through the relai.' 226, which in .ated for the third digit 0, whereby the switching repeater L', by means of the line relay '18, opens the circuitof the line relay 125 a corresponding number of times. Each time the relay 125 is deiinergized, a circuit is 4 closed through the vertical magnet 120. The

relay 226 being slow acting does not dencr gize during the momentary interruptions of its circuit. The circuit through the vertical magnet 12() extends from ground G14 through the spring 140 and its back contact,

springs 11i-1 and 142, relay 143, vertical magnet 120 and the side switch wiper 144 (in first position) to battery X. The vertical magnet receives ten impulses over this circuit'and operates to raise the shaft wipers opposite the- 0 line of bank contacts. The relay 143, which is included in the operating circuit of the vertical magnet. remains in its energized position during the entire time that impulses are being transmitted through it and operates lo close the circuit of the pri vate magnet 122 as ollowszfrom ground G15 through the springs 145 and 1-16 and the private magnet 122 to battery X. After the last impulse has been delivered, the relay 143 opens the circuit of the private magnet 122, which, upon dciincrgzinu. permits the side switch to pass from first to second position. The movement of the switch wiper 144 from first to second position transfers the battery connection from the vertical magnet 120 to the rotary magnetl 121;

The calling subscriber now operates his calling device for the last digit' 0, whereby the switching repeater L', by means of the line relay 18, opens the ,circuit of the line relay 125 a corresponding number of times. Each time the relay 125 is deiinergized, a circuit is closed through the rotary magnet extending from ground (l14 through the spring 140 and its back contact, springs 111 and 142, relay 143, springs 117, rotary magnet 121 and the side switch wiper`144 (in second position) to battery X. The rotary magnet receives ten impulses over this circuit. and operates to rotate the shaft wipers upon the line of the called subscriber. The relay 143 operates in response to vthe impulses for the digit in the same manner as for the previousdigit, to cause the private innagnet 122 to advance the side switch to third position. side switch wipers 148 and 149 with their third-position contact points, the line con- By the engagement of the nection is completed with the called line.

Upon the engagement of the side switch wiper 150 with its third-position contact point, a circuit is completed through the cut-oit winding of the called line switch.

The said circuit extends from ground Grle through the side switch wier 150 (in third position), private wiper 11 and the cut-oil' winding 151 to battery X. 'The cut-oli' y winding of the called line switch, upon energizing, operates to disconnect, the line relay from the called substation. The connection of ground G1 with the connector private Y bank contact of the called line prevents the called line from being seized by some other connector switch. By the engagement of the side switch wiper 144 with its third-position Contact point, the circuit of the ringer relay 124 is closed. Said circuit extends from ground G through the interruptor 152, relay 121, spiings 153 and the sideswitch Wiper 144 (in third position) to battery X'. The ringer relay disconnects the calling line from the called line and bridges the ringing current generator O across the called line to signal the called subscriber.. The' ringer relay is energized only intermittently through the medium of the interrupter 152. Upon the response of the called subscriber his line is provided with talking current through the windings of the batik-bridge relay 154, which, upon energizing, closes a circuit through th'e ringer cut-oil' lelay 155. This circuit extends from ground G1 through the side switch Wiper 150 (in third posltion), springs 15G and the relay 155 to battery X. The relay 155, upon energizing, interrupts the circuit of the ringer relay at the springs 153 and closes a locking circuit for itself through the springs 157 independent of the springs 156. The energization of the relay 154 also reverses the How of current in the trunk from the switching repeater L. Since the current in the right-hand Winding of the relay 51. is now reversed, the two windings help each other and the relay' 51 becomes operatively energized, and in so doing reverses the current. in the line to the substation T.

After'the conversation is completed, the connection is released by the hanging up of the receiver at the calling substation in the following manner: 1V hen the receiver at the substation '1" is restored tc the switch-hook,

.the separation et the switch-hook springs destroys the energizing circuit of the switchincense 175 of the connector P. A circuit Amay new be traced 'from ground im tl'nough the lower winding of the relu),` 175. springs 17h und il?, rf'uulucl'or 171ml, ciprilll. springs 179 und 32. springs lli i'i'l li' to und through the substation TQ spring; I' s und lli, springs Q2 und 150, wiper l.l'l,conihuftor 1H',springs and 1&3 und the upprr winding of the relay 175 to battery X. The relay 175, upon energizing over the above circuit, closes u, circuit through the relay 184, The relay 184, upon energizing, affords a holding circuit for the holding winding` 34 of the line switch EYand also places a guarding potential upon the bank contacts in the master switch bank which is associated with the connector P. This holding circuit muy traced from ground G2" through the springs 12d-l, conductor 185, bunk contact 186, wiper 65. springs 14:37 and 31, springs l2 und 33 und the holding winding Si to battery X. A brunch of the above circuit also extends from the conductor 185 to the bank Contact 188. A second branch of ihr above circuit extends from the spring 31 through the springs 75 and the lower winding ofv the rc lay 73 to battery X. The line rela@7 18. upon being disconnected from the line, denergizes and opens the circuit of thc reluy 2S, which in turn, upon denergizing, removes ground G'q from the conductor 35. which allows the secondary switch H to return to normal position. At the same time the selectors l and J release, as previously explained.

` Upon the subscriber at substation T celling the last two digits of the called number, the action ofthe connector P is the same as ex lained for the connector F'.

'pon the completion of the conversation, the restoring of the receiver to the switchhook at the substation T opens the circuit of the line relay 175, which, upon denergizing, opens the circuit of the relay 184e'. The rela 184", upon denergizin removes round 2, which causes the hol in windm 34 to. denergize `and allow t e line swltch E to return to normal. The removal of ground G2 also opens the circuit of the lower winding of the relay 73, which, upon denergizing, removes ground G from th circuit of the relay 174. The relay 174, upon denergizing. closes the circuit of tho release magnet and the switching repeater releases, as previousl expieined.

In the present disc osure the line switch Z is for the purpose of extending u connection from the main exchange to an idle connector switch, us 'is shown ut P. As reviously explained when the connector is busy there will be u ground potential upon the muster switch bank contact 18?. which corresponds to seid conneuior. if the nies ter switch U el `this time happens to hold the idle line u :h plungers oppositethe trunk line leaning to the switch P. it will in the known numner to 'carry said plnngers opposite the next idle trunk which lends to another connector, similar to P. ds is well known the line switch Z' li is ne cess through its bank contacts to a. number of connectors P, the master switch U bein the `medium for determining the idle on( busy condition of said connectors. It will now be assumed that nnector P is idle und that the plunger shown) of switch Z is standing opposite the trunk line shown leading to saidY connector. In responding to a connection from the main exchange the switch Z will operate to thrust its plunger opel Vinto the bunk of contacts thereby extending the connection to the connector P. The operation of Z is similar to that explained in connection with the line switch E'. The line relay 175 and release rcluy 181"x are thereupon energized. The relay 184 upon energiniiig. extends u holding ground from G2 through springs 184, bunk springs closedby the plunger, und the holding or cut-orf winding of seid switch Z to the battery X. A brunch of this circuit extends to contact 188 to cause the muster switch to move the renniiniug plungcrs away from the seized trunk line. Another branch of this circuit :friends over conductor 185 to the bank contact 186 of switch L', to prevent seid switch from seizing connector P us long as it is thus connected with switch Z.. The calling subscriber then operates the said connector P in the known manner to find the desired celled line in the branch oliice. i

In the foregoing description it has been assumed that the switching repeater is used in u ten thousand line system, or in esystem in which the subscribers numbers comprise four digits, und that the brunch office is not above one thousand lines. For this reason the switching repeater must be capable of o* erating upon the second digit called. l hen used in a hundred thousand line systern, or in a system in which the subscribers numbers comprise five di ts, andthe branch oflice is not above one t qusand. lines,- it is necessary for the switching repeater to be capable of operating upon the third digit cu led. For this reason, when operating in u live ligure exchange, the relay 73 is re pissed by the relays 189 and 190 shown in 7. The conductors 191 and 192 extend to the buttery X; the conductors 193 and 194 extend to the release magnet 74; the conductors 195 und 196 extend to the spring '31; the conductor 197 entends to the ban contact 70 and the conductor 198 extends to the Contact 173 and multiples thereof. We will suppose that the subscriber to be called, who is in the samebran'ch office as the cull` ing suhscrihcr. has the number 55300. Upon culling the First digit h, the wipers of the switching repeater will come to rest upon the hunk contuct and n circuit will be termed. when the private magnet deencr gizeh?. troni ground (V through the `prin =js` lli'. tiel and titi, wiper lli. bant; contact ill, conductor lili'. .springs ttltl and 21K', the upper windin r ot tlnmrelay ISU, unnlurtor lill. release magnet Tl and the springs ltifi to battery X. Thereupon the switching repeater will be released and the relay .ltltl will be locked up orar a circuit extending Al'roni ground il through the springs *29, Btl and ill. conductor lili'. spring 201, lower winding.,f ol the rela)` 19H and the conductor lill to battery X. llpon calling the .second digit .7, the wiperottheswitchingrcpcatgr will come to rest upon the baul; contact fl and a circuit will be formed when the prii'ate magnetV denergizes from ground tl" through the `springs tl?. tiH and (it), wiper G5. bank contact itl. coinlnctor lili', springs la!) and 202, springs tland til, winding` of the relay lltl. conductor lll, release magnet Tl and the springs It-'i to battery X. 'there-- upon the switching repeater will be released and the relai' tot) wiil be lorkedup mer a circuit' extendingy from ground (ii th nigh the springs Btl, prings itl and Ill, conductor lSltL ysprings' 20.3, [on er winding ot the rela lltl and the conductor 19:3 to battery i "llnv energizat ion ol the relayI llltl also places ground from ground (ift through the springs ti'li and l'l, springs tu and 199, conductor lili io the bank contact Tt). A circuit is also closed troni ground (l2x through the springs :IVI am] the conductor ille to the Contact: lTi and nnilt iplrs` ot same. lipon callingr the third dien $3. the` switching repeater will rome to rest upon the first idle Contact? in Ilnthird imei olt bank contacts and the sa itching relay lil will operate to connect tin railing:` line with a connector in that group. as prciiously explained. The rcniainder oli the call and the release of the switches` will now take place in the manner previously explained.

While l have illnsiratet'l my invention by the use nt' a number in which the first two digits` are the same, it will readily be seen lij.' any one versed in th i. art that` by changing the position of the conductors '19T and 20S. the s\\'itrliin, r repeater could be made to release upon any combination ott the first two digits calledy Furthermore, while l have illustrated my invention in connection with swirl-hes of well-laufm'n types, it will, 0ll L'UIII'SL. llt* tltlfleist'nail that I (l0 not wish to be limited ao the wen-t construction showi and described, but that various changes and modifications will readily` suggestV themA .selvef'` te those :drilled in the nrt without depar-titrer from the .spirit ot' my invention.

li'hat lV claim as my iurentiou isf-A l, lin a telephone system. a line. a switch for said line. a sei-ond line. a switching relay for said switch. means lor operating the `switch and l'or thereby preparing a circuit l'or `said relay and for then releasing the switch. and means whereby when the `switch is again operated said relay is operated over said prepared circuit to enable the first and second lines to be brought, into connection.

In a telephone system, a line, a pro- `Lrcssirely movable switch for said line, a second line, a switching,r relay for said switch, means for operatinf.;r the switch and for thereby preparilngr a circuit; for said relay and for then releasing the switch, and means whereby when the switch is again operated said relay is operated over said prepared circuit to enable the first and second lines to he brought into connection.

il. ln a telephone system, a line, a switch tor said line, a second line, a switchingr relay t'or said switch, means, involving a` magnet and a eontaclly tor operatiingr the switch and for thereby preparingr a circuit for said relay and t'or then releasing the switch, and means whereby when the switch is again operated said relay is operated over said prepared circuit` to enable the rst, and second lines to be brought into connection.

4. ln a telephone system, a line, a switch for said line, a second line, a switching relay for .said switch, means involving a magnet` and a pair of contacts, for operating the switch and for thereby preparing a circuit for said relay and for then releasing the switch, and means whereby when the switch is again operated, said relay is operated over said preparaat] circuit to enable the first and second lines to be brought into connection.

5. In a telephone system, a line, a switch for said line, a second line, a switching relay for said switch, means, involving a magnet and a potential controller, for operating' the switch and for thereby preparing a-circuit for said relay and for then releasing the switch, and means whereby when the switch is again operated said relay is operated over said prepared circuit to enable the first and second lines to be brought into connection.

t?, In a telephone system, a line, a switch for said line, a second line, a switching relay for said switch, means for operating the switch and for thereby preparing,y a circuit for said relay and for then releasing the switch, and means, involving a Contact, whereby when the switch is again operated said relay is operated over said prepared circuit to cnable the first and second lines to be brought into connection.

7. .In a` telephone system, a line, a switch for said line. a second line, a switchingr relay for said switch, means for operating the switch and for thereby preparing a circuit for said relay and for then releasingr the switch, and means involving a magnet and a progressively movable contact, and means whereby when the switch is again operated 8, In :i lehphrnm s ififiii n hun? :i wiiirh for said lim.y A Seconii lim; u .switwhmg relai; for said switch, nimmst, im'nlvinyj :1 xilzagit and a Contact, mechanism fm* mingling @iw @nimmt tu :my (me of ihrem im@ n, r; mening im' (moaning im :11h-1l 'il thereby prupnring a minuit lfm' will x'f-li nml for then rvhslsing w Hwitfxhl nl www whereby when thv` swifrh inf: A .Malawi Saul IQlxy ifi opel-:lim mmh-:i circuit tu enxlhlu they h* rl Ei to he ln'uught into conn.'

9. In :i telephone syslm, a @Il wviiwii for Said line, a Secnd line, a switching rel@ )u for said sfwilrbhj menus. im'nlviilg ai lunghi-l and l paix' of commis, mechanism im: @uw trnllixig one of said um i i' thu misleid $0 Suhl mmm: thm hf. n ai w. 11i :mil l1: n? siam; Talen wlwizffir imm 'ahh mi W-h Siifl "F-lsllvfl iii-fi mid v cirifiai; te, amable: the limi. nini man to hil'jrnught intn ummm-*Miia lil lu :i telephone swt m, a linfi for said lim", n wrfam /a ching ly for said mik-lh mmm. if 'nvigg magi :and :l airviiil multi-IEW fr if?, t switch :mil fm' lhei'ew for will re :wail {w1- Y swiilrh. mail www whemlly wh i fig; in uprfmtcd miel relug' ila l said el'eiplufczl circsin @n.ish second lines to he bumght. inw l ne mi,

1l.. In a telephone system, i; liga..j i Swich for Said line, a second line9 :i switc ling rw lay for said Switch, 'means im upemning the Swilch and for thelly @flaring ciu fuit foy said rela. melma i' lying u ru leasing pnwl fwr then milf. ,iwiln :md means wlm'rohzs lum lim again (spe-wiwi said relay is; giur-@wil wr sind preparwl fil-cui'i to niebla the {h1-: :nul mfg and linnn; i0 he hlollghl i'a mm! than l2. n a teleplmne systm, :i iii-.wi :i Minh for Said line, a second line, Lewin-,hing relay for said swich, means for apeiwting the Switch and for thereby preparing n @irl-:m for said relay and fer' hm) wlvwing; ih@ swim-h, and means, inmlring; a minimal im!! mechanism for adjiisting tiifmntsul m :my om' of three pofsitiims, 'hm'ely wlmi thv` Switch is again opmntoel sail Yn-luy i5 upm' ated ov r said prepared cin-,uit lo onnhlu llufirst and second lines tu hij bxwngjhi irate) ffmnectzion.

13. In a, telephone s stem, u line3 n Minh for said line, a, secon( lima u tub' g ire Illy fr said Switnh, maar iswili and for the lf im* Wlill rainy :imi lm limi lvlvsieiing 'Llw 1mi Hwang, ilwolviing u, progressively i fihir nimmt whvrchy when ill." mitch is again upm-ated said relai; is; op mated over said prepared Ciicuit t@ enable lw iirst und ssccunl lines to he hrought 'mtu fi'l'll il, 2f: :i Mh'ilnwnfe s mlem, li lineI n Switch iwf n il! lima :i i mit, :l Schmid line, n rswitch milch, menus, inulving hafi and a iai-gilet` fm- ;iml fm1' herehjv prefu mill Ialuj.' nm] im' them .77 1mi miauw involving mi" mili shzifl5 whereby i l i seguia uplaraitwi said relay :said plapmml Circuit tu Iirsi and @wund limiti iu hv cr'iumeigi ihn. .il Y l fplmlw jgslem, :i line, a. svi-01ml 1 'fria liar the, til-t li e', for locating iimf, will ,Swiuh comprising Y @milling this iwi iiiws'in he um cmmwllmi MTK-r The second line limj. d uiiwuir im rmitmling Said mums mhifsiilml ley thv switch when in Eppure .will a' s, i1 anni means @leaning hu @wich whereby which il; 11 misil :1mi again oymratml am is smallville@ m'ei' fluid pw9 "im, a liuc, fi seuoml lill@ i ingrw mumhli that hfet` hun fur l *mgl* the wculil liiw3 Suid .switch mmh 3m ing iurenfw, fm' enabling the two lines to im vimigli ini@ @annali-:m M201' the second limy is lmflwd a inuit fur zenitrulling said immls. lilczms cfmtl'olleil h5" the switch, thruiagh a Contact un Huid shaft, when 0p umts-fl im prepare: said circuit und means for ihren wlmeing @im shaft iilll-reby when the sin: lz nii-ascii :mii :igziin omiaed Suid rst inv-ubi is mima-@Mod nvm' said prepared Cir- @uit uml 1m-ri' annahm contant im the shaft.

wir, im; mechanism associated with said iieili, si rfi-mgmt, fm wntl'ulling said nuxlisu'y switching mechanism, said switch bein-2 provided with means for moving the sWtc 1 is pcgmre, the circuit mi' Suid magnet, menus a" hffn ivlasing the switi'h und for again ivy-dirig the switch t luc-ate the second 1w :mi tu operata said muguet tu enable ln fi1-1t mul Second lineas t0 be wimected.

'l' in :m autmxmtiu telephom '1ysten1, :i sii'illfl: provirlml wh a m'ogres- Yely mm*- ahli; shaft, contact makers on sami shaft, i1 'gelei-15e mechanism assnuiuted with said milt Qontavts associated with said contact mir circuits extendi therefrom, a line Vismsuted with mid swim i7 awimhing means acting said line sume of said contact makers, a magnet for controlling4 said switching means. a circuit tor sai'` magnet. means for operationr said progres; sively movable shaft and lor releasing@- the same and for at the same time pri-,paring the circuit ot said switching magnet` whereby when thc switch is airain operated said line may be extended to said contact makers.

ill. ln an automatic telephone trunking system, a trunking switch provided with a progressively movable contact maker, a release mechanism associated with said switch, n contact associated with said contact maker, said release mechanism comprising a magnet for controlling the said mechanism, a circuit for said magnet including said contact maker, :mother contact, a circuit :for applying a potential to said contact, a switch in said last circuit for controlling the same, and means associated with said first Contact for operating said switch.

20. In a, telephone system, a switch with a progressively movable contact maker, a line associated with said switch, an impulse sending device for scndinijr a plurality ot' sets ot impulses to operattl said switch to connect said line with another line, a mechanism associated with said contact maker for releasing the same, means for advancing the Contact maker and for then operating the release mechanism to restore the Contact maker before the connection is completed in response to the first set of impulses, and for operating the switch in response to the remaining series of impulses to complete the connection.

21. In a telephone system, a line, a switch for said line, a second line, a switching relay for said switch, means for operating the switch and for thereby preparing a circuit for said relay, and for then releasing the switch, said means involving a magnet and a bodily movable contact controlled by mechanism for adjusting said contact to any one of a plurality of positions, and means wher by when the swltch again operated the said relay is operated over said prepared circuit to enable the first and second lines to be brought into connection.

22. In a telephone system, a line, a switch for said line, a second line, a switching ren lay for said switch, means for operating the switch and tor thereby preparing` a circuit for said relay and for then releasing the switch, aid means involving a magnet and a. pair of contacts. one of which contacts being bodily movable and controlled bv mechanism for adjusting the said` movable contact to any one of a plurality of positions, and means whereby when said switch is again operated said relay is operated `over said prepared circuit to enable the first and second lilies to be brought into connection.

23. In a teiephone system, a line, a switch for said line, a second line, a switching relay for said switch, means for operating the switch and for thereby preparing a (.ircuiA tor aid relay and for then releasing tli- `switch, means wherein when the switch iiagain operated said relay is operated over said prepared circuit to enable the first and second lines to be brought into connection, all ot' said means including movable con- Iact makers tor engaging stationary com lacts, lines tcrmimtting in said stationary contacts, busy test circuits associated with said lines, means responsive, when the switch is last operated. for moving said makers into engagement with one ot' said lines and if the line is busy, for autonmtically advancing the contact makers through the instrumentality of the corresponding busy test circuit onto the next line.

2i. ln a telephone system, a line, a progressively movable switch for said line, a second line, a switching relay for said switch, nie-fins for operating the switch and for thereby preparing a circuit for said relay and for then releasing the switch, means whereby when the switch is again operated said relay is operated over said prepa-red circuit to enable the first and second lines to be brought into connection, all. of said means including movable contact makers for engaging stationaryy contacts, lines termiA nating in sd `stationary contacts, busy test circuits associated with said lines, means responsive, when the switch is last operated, for moving said makers into engagement with one of said lines and if the line is busy, for automatically advancing the contact makers through the instrumentality of the Corresponding busy test circuit onto the next line.

In a telephone svstem, a line, a switch for said line, a. second line, a switching relay for said switch, means involving a magnet and a contact, for operating the switch and for thereby preparing a circuit for said relay and for then releasing the switch, means whereby when the switch is again operated, said relay is operated over said prepared circuit to enable the first and second lines to be brought into connection, all of said means including movable Contact makers for engaging stationary contacts, lines terminatine,r in said stationary contacts, busy test circuits associated with said line, means responsive when the switch is last operated, formoving said makers into engagement with one of said lines and if the line is busy, for automatically advancing the contact makers through the instrumentality of the corresponding busy test circuit onto the next line.

Q6. In a telephone system, a line. a switch for said line, a second line, a switching rolay f or said switch, means involving,r a magie net and a pair of contacts, for ope atingr the switch and 'for thereby preparing a circuit for said relay and for then releasing the switch, means whereby when the switch is again operated said relay is operated over said prepared circuit to enable the tirst and second lines to be brought into connection, all of said means including movable con- Atact ,makers for engaging stationary contacts, lines terminating in said stationary contacts, busy test circuits associated with said lines, means responsive. when the switch is last operated, for moving said makers into engagement with one ,of said lines and if the line is busy, for automatically advancing the contact makers through the instrumen tality of the corresponding busy test circuit onto the next line.

27. In a telephone system, a line. a switch for said line, a second line, a switching relay for said switch, means involving a magnet and`a potential controller, for operating the switch and for thereby preparing a circuit for said relay and for then releasing the switch, means whereby when the switch is again operated said relay' is operated over said prepared 4circuit to enable the rst. and second lines to be brought into connection, all of said means including movable Contact makers for engaging stationary contacts, lines terminating in said stationary contacts, busy test circuits associated with said lines, means responsive when the switch is last operated, for moving said makers into engagement with one of said lines and ii the line is lbusy, for "automatically advancing the contact makers through the instrumen- `tality of the corresponding hnsy test circuit onto the next line.

28, In a telephone system, a line, a switch for said line, a second line, a, switching re lay for said switch, means for operating the switch and for thereby preparing a circuit for .said relay, means for then releasing the switch, means whereby when the switch is again operated said relay is operated over said pre ared circuit to enable the first and second lines to be brought into connection` all of said means including movable Contact makers for engaging stationary contacts, lines terminating in said stationar 7 contacts, busy test circuits associated with said lines, means res onsive, when the switch is lastoperated, or moving said makers into engagement with one ott said lines and if the ne is busy, for automatically advancing the contact makers through the instrumentality of the corresponding busy testcircuit onto `the next line.

29, 1n a telephone system, a line, a switch 01* said line, a second line, a switching relay or said switch, means for operating the sivitch and for thereby preparing a circuit ksaid relay and for then releasing the switch, means, involving a contact, whereby 'when the switch is again operated said re lay is operated over said prepared circuit to enable the first and second lines to be brought into connection, all of said means including movable contact makers for engaging stationary contacts, lines terminating in said stationary contacts, busy test cireuits associated with said lines, means responsive, when the switch 1s last operated,

for moving said makers into engagement with one ofisaid lines and if the line is busy, for automatically advancing the contact makers through the instrumentality of the corresponding busy test circuit onto the next line.

30. ln a telephone system, a line, a switch forsaid line, a second line` a switching relay for said switch, means for operating theswitch and for thereby preparing a circuit for said relay and for then releasing the switeh, said means involving a magnet and a progressively movable contact, means whereby when the switch again operated said relay is operated over said prepared circuit to enable the first and second lines to he brought into connectiominovalgle contact makers for said switchconengaging sta-- tionary contacts, lines terminating in said stationary co tarts, busy (est circuits associated withlsaid lines, means responsive, when the switchis last operated, for moving said makers into engagement with one of said lines and if the line is busy, forr automatically :ulraucing the Contact makers through the instrumentality of the corresponding busy test circuit onto [he next line.

ill. In a telephone system, a line, a switch for said line, a second liuc, a switching relay for said switch, means, involving a mug-- net und a contact controlled by mechanism for adjusting the contact to any one of three positions, for operating the switch and for thereby preparing a circuit for said relay and for then releasing the switch, means whereby when the switch is again operated said relay is operated over said prepared circuit to enable the first und second lines to he brought into connection, all of said means including movable Contact makers for engaging stationary contacts, lines terminating in said stationary contacts, busy test cir cuits associated with said lincs,'mcans responsive. when the switch is last operated, for moving said makers into engagement with one of said lines and if the line is busy, for automatically `advancing the Contact' makers through the instriuncntality of the corresponding busy test circuit onto the next line, r

32. ln a telephone systen'i, a line, a switch for said line` a second line, a switching relay for said switch, means involving a magnet and a pair of contacts, one of which contracts is controlled by mechanism for adjusting the Contact to any one `ot three vpositions, for operating the switch and for there' by preparing a circuit Jfor ,said relay and for thcn rclcasing thc switch. means hereby whcn thc switch is again operated said relay is opcratcd ovcr said prcparcd circuit to cnahlc thc tirst and sccond liucs to lic brought into conncction. all ot' said incans including movahlc contact makcrs tor caigaging stationar)` contacts. lines tcrniiuating in said stationary contacts. bus)Y lest circuits associatcd with said lincs. nicans responsive. when the switch is last opcratcd. for moving said malv'crs into cngagcmcnt with onc ot' said lincs and it' thc [inc is husv. for automatically advancing thc contact makers through thc instrinncntality of thc corrcslionding husv test circuit onto the next line.

325. ln a tclclihonc sys-tcm. a line` a switch for said liuc. a .second liuc.` a switching relay for said switch. means. involving a inagnct and a circuit controllcr.y for opcrating the switch and t'or lhcrclrv lircparing a circuit for said relay' and for thcn rcleasing the switch. means wherchy when thc switch is again opcratcd said relay is opt-rated over Said prcjiarcd circuit to cnahlc thc irst and Second lincs to bc brought into connection. allot' said lncans includingr niovahlc contact makers tor engaging stationary contacts, lincs tcrminating in said stationary contacts, busy tcst circuits associatcd with said lines, means responsive. when thc switch is last` operated. for moving said makers into engagement with one ot' said lincs. and il' thc line is busy, for automatically advancing the contact makers through thc instr!uncntality of the corresponding busy tcst circuit onto tho next line.

34. ln a telephone s vstcm, a liuc, a switch for said line, a second lin'c, a switching relay for said switch, mcans for opcrating the switch and for thereby prcparing a circuit for said relay, means involving a rclcasing paw] for then releasing thc switch. and moans whereby when the switch is again operated said rclay is operated ovcr said prepared circuit` to cnable the first and second lines to loc brought into ci'mncction. all of said means including inovahlc contact nialtcrs for cngaging stationary contacts. lincs terminating in said stationary contacts. busy test circuits associated with said lines. means responsive. when the switch is last opcrated, for movingr said makcrs into engagcment with one ot' said lines and it thc line, is busy for automatically advancing the contact makers through the instrumentality of thc corresponding busy test circuit onto the next line.

35. 1n a telephone s vstcn'i, a line. a Switch for said liuc. a second lino. a switching rela)r for said switch. means for oiierating the Switch and for thereby preparing a circuit forfsaid rclay and tor thcn releasing the switch. and means. involving a contact controlled by mechanism for atliusting the con.` tact to any one nl" three positions1 whereby when thc switch is again opcratcd said i'rlay is opcratcd over `said iil'cparcd circuit io cn. able thc first aud sccond liucs to hc brought into conncction, all oil said uicans including movable contact makers i'or cngaging stir tiouary contacts. iincs terminating in `said st'ationarvv contacts` lulsy test circuits asso ciatcd with said lincs, nicans. rcsiionsivc. when the .switch is last opcratcd. 'for moving' said malicrs into cngagcmcnt with onc ol' said lines and if the line is busy. tor autoniatically advancing thc contact malo-rs through the instrumentality ot' thc corrcslionding busy tcst circuit onto thc next linc.

rltl. ln a telephone s vstcni. a liuc. a switch font-:aid liuc. a sccond liuc. a switching relay tor said Switch. means for operating thc switch and t'or thcrchy preparing a circuit Jfor said relay and for then rclcasing thc switch. and means. involving a progrcssivclv movable contact. whereby whcn thc switch is again opeiatcd said relay is oiicratcd ovcr said prepared circuit to cnahlc thc` iirst and sccond lines to he brought into connection. all of said incans including movahlc conlact malo-rf` for cngaging stationary contacts; liucs tcrniinatingin said stationary contacts` busy tcst circuits associated with said lincs, mcaus rcsponsivc. when the switch is last oicratcd. l'or n|o\ ing said niakcrs into cngagcN mcnt with onc ot said iincs and it thc liuc is busy, t'or automatically advancing thc con tact makers through the instrumentality ot' the corresponding busy tcst` circuit onto thc lie/Xt; line.

37. In a telephone system, a liuc. a switch for said line, a shaft, a second line, a switching relay for said switch` mcans involving a contact on the shaft and a magnet, ll'or ola-rating thc shaft and for thereby prciiaring a circuit for said relay and for thcn rclcasing the shaft. and means. involving another contact on said shaft. wherchy when the shaft is again operated said relay is o|icratcd ovcr said preparer] circuit to enalilc thc first and second lines to be broughty into connection. all ot' .said nic-ans including movablecontact makers for engaging stationary contacts. lines terminating in said stationary contacts. busy tcst` circuits associated with said lincs. moans rcsjionsive, when thcA switch is last Operated. for moving said nialtcrs into cugagcmc-nt with one of said lint-s and it' thc line is busy. for automatically advancing the contact makers through thc instrumen tality of thc corresponding busy tcst, cir cuit onto the next linc.

38. In a telephone s vsteni. a lino, a sci-ond line. a switch for the first. liuc for locatingr the second line` said switch comprising means for enabling the Iwo lines to hc brought into conncction after the scconil liuc is lo atcd. a circuit, for controlling said means. mcans` controlled by the switch whcn olicratcd to prcpare said circuit, and means llt) for then releasing the swlel wher-elly when the. switch is released and again upemlml said first means is eontrollerl mes: Held my pared circuit, all of` seid means E; :eline: mumble. Contact makers l'm engr tonzu'y entfneis, lines lerne nalin stzaoniueuntncl, busy lern ein* elated with said linee. wenn when the ewiteil is lari; @peinte inn' suel nmliers inw engamerwnf uf ,mid lines nml 'il' ille line mdlieully mlfanelng the een thrfnxgh the nstrumentely el the www spending buey test eircu enn lle nem; l' p 39. ln a telephone tenu n nner f, und line, n Switch prmnerl 'wlll l slm-ly movable Shaft fin ille lire` l lmzning the fewmd line, nel mell ing nneml for enfxlvllng ill@ uw V lll-engin inte ennneellzn: elta-r ne le loealfwh einen, im* www@ merma means eni'elled l tllrnngh n @when nn sul@ Slm 1 i atlell t premle said elrcllil :mil wenn@ in then releasing the shaft, whereby allen ille shaft. is released and again npereiefl mill limit means ls controlled over seid 3i i elrmi and over another cnnzu' er all of sami mmm including lnzwnllle --mf makers mengnglng glm'zae'f' lines termlnntlng in :miel

Simile mets., im@ wh ell-mine a-.se-inuawl lines, meme; responsive. when Ille lust (unarmed, 'ler :nerim-A" :nifl n el'lgiagfeinent viirll une ul' l Luni l. lne busy, fm' anlennntlealljv mirra f Contact nmlcers through the lnmrlmen nl! the en "Sponfing lmsy lest vir-cnn 'llae next line.

(2. ln a gvleplnnw x-zwtenn -1 lllA owl line; n when for Mnl lll linrjyY swtellng meulnwmn miel sul? muggne; fer nuXll-nry swfelnng meclnznn-m, mi being' prnvllled with mean, nr man swll'en te prepare the elreult ni' miei muy lg means for then releasng me when fnl r again operaallng the ewel; Le l" te llw nml line :mel ln operaie, said nel able ln: lin-l1 :und seeond lines l neeiecl. minable C-{mtdl mulini@ f nwitell fm* engaging srMemmj-,f (wandeln-h: lines eranlnang in snif! -hllfnmry w11- :1rs,lm5 we erenltA um 'mlwl wlln un line, mmm resnfrnhlve. when The nulle les! n, ,e:`=lell, lor lnevine; .will nr'.

enejngelnem with one nl' miel linee anni the line l muy. fm' uutfpnmvnllf; mi me; in;

The: eunfzxel,` makers hrongll alle imm-Innenial'atgv 0l' the emrespondmg exi` e'nivnlt wam.

1 nswjngnllel with Suid eeutzwl; makers, Siemlng therefrom, t1` line ennneet saifl switch, swtehng means for rff @nifl line with some nf Suid emr Y .l u nmgnet fer eentrellng en'nl r len-4ans. :1 eireuir. fee Said magnet en npvrning' Said progressively mm` nhl fer releasing the same und wie time prepari .Y e, Circuit ell me lling annggne, whereby when the A :ne uperelerl ad line may be eX l miel el M* makers, linee lerml 1-1 ln wel elle enary contacts. leas-v Lest lated with Suid lines, mee rethe swch le last upefned. "Alf nieke'w inw engrfwenaelll l,.r";l=nl" nlif:1s:re;nlln

ein"

ilmne sjfslenn :l lne, u #n il'll und lne a swehng re- Win EL Inemw l'm meratng llxe nel rmi igllereby preparing n erenl and fer then relenslng tne whereby when ln Swfznll 'id relai( is npernerl over .remt to enable lln und e, m iw breng/:lll lulu ennneutmn 1f| nb V-mnprisngr :ilse n device im' e ne. circuit of Said relay in its enmlon during the interval heelens''ng of the swlelx ln the we and lille uperatlnn of ille ww itch flex: l

n e eleplnme System. n lne, n enlfrlr l ll u n Semml lim; n swlelnng re -"fllrl`\. inennm lnvsllvng :L 11mg'- Mznm'l for uperutx'le the swilelx 

